Valve control for discharge of finely divided material from vacuum to atmosphere



Jan. 23, 1968 M. GORDON 3,365,240

, VALVE CONTROL FOR DISCHARGE OF FINELY DIVIDED MATERIAL FROM VACUUM TO ATMOSPHERE Original Filed Nov. 1, 1965 H7770.) PHE/P/G INVENTOR N964 60/10o/v FTTO F YEYE' United States Patent This is a continuation of application Ser. No. 505,926, filed Nov. 1, 1965, and now abandoned.

This invention relates to improvements in a discharge valve structure for handling and controlling intermittent movement of material from a reservoir chamber or hopper to a discharge zone, and more particularly to an arrangement, in series between said chamber and zone, of a first valve, a surge chamber and a second valve.

The invention utilizes valves of the type controlled by differential pressure on the upstream and downstream sides thereof, greater pressure on the upstream side being effective to open said valves and greater pressure on the downstream side being eflective to close said valves. By placing the upstream and downstream sides of the first of said valves in communication with said reservoir chamber and surge chamber respectively, and by placing the upstream and downstream sides of the second of said valves in communication with said surge chamber and said discharge zone respectively, this invention makes possible a simplified control cycle in which a lower fluid pressure in said surge chamber causes opening of said first valve and closing of said second valve to drop material from said reservoir chamber into said surge chamber, and a higher fiuid pressure in said surge chamber causes closing of said first valve and opening of said second valve to drop material from said surge chamber to said discharge zone.

This invention is particularly useful for discharging finely divided material from a dust collector or pneumatic handling reservoir, under vacuum, to a discharge zone at atmospheric pressure without significant loss of vacuum. A preferred form of valve for such use is shown in my Patent No. 3,167,089, granted Jan. 26, 1965.

Other objects and advantages of this invention will be apparent from the accompanying drawing and description, and the essential features thereof will 'be set forth in the appended claim.

In the drawings:

FIG. 1 shows one embodiment of this invention in central sectional view and in somewhat diagrammatic form; while FIG. 2 shows a portion of FIG. 1 with the valves in a different actuated position.

At is shown an air-tight hopper or reservoir chamber, which may be a dust collector or reservoir in a sys tem for pneumatically handling finely divided material, and having an inlet and outlet connected to a vacuum source. The reservoir chamber has a bottom outlet where the discharge valve structure of this invention is connected.

This novel structure comprises, in series, a first valve 13, a surge chamber 14 and a second valve 15. The attached claim defines a passageway extending from an inlet opening 16 to an outlet opening 17. This passage way is air-tight save for the action of valves 13, and 19 at certain times as will be described.

Valves 13 and 15 are opened or closed by differential pressure between the upstream and downstream sides thereof such that, as shown in the drawing, a greater pressure on the upstream side will cause opening of each valve, and a greater pressure on the downstream side 3,365,240 Patented Jan. 23, 1968 will cause closing of each valve. A preferred form of valve, especially for handling finely divided material is illustrated in the drawing and each comprises a pair of flat lips 13a, 13b, or 15a, 15b of flexible rubber-like material depending from an integral sleevelike upper portion 13c of there being a smooth opening through each valve for uninterrupted flow of finely divided material. Each pair of coacting lips have linear terminal portions which normally lieclose together and are pressed close together in sealed relationship by predominating pressure externally of the valve, or opened by predominating pressure internally of the valve. The rubber of the lips is sufficiently soft and flexible that they seal around any finely divided material which might be caught between them. stiffening members 25 embedded in the rubber prevent the valve from being sucked upwardly by internal pressure.

The above-described structure lends itself to a very simplified control according to the teaching of this invention. Referring to the drawings, means is provided to impress a fluid pressure selectively at higher or lower pressure levels in the passageway including surge chamber 14. This comprises conduit 18 leading from surge chamber 14 to a three-way valve 19. One position of valve 19 (FIG. 2) connects conduit 18 with a source of lower pressure or vacuum 20, while another position of valve 19 (FIG. 1) connects conduit 18 with a source of higher pressure or atmosphere 21.

In operation, valve 19 may be manually controlled or it may be controlled automatically to provide a timed cycle. Illustrated diagrammatically is a motor 22 which, through gear reduction 23 drives shaft 24 which in turn rotates valve 19 alternately into one or the other of its two positions described above. The port in valve 19 may be circumferentially extended to apply either vacuum or atmospheric pressure to surge chamber 14 to the time intervals desired.

It will now be obvious that when higher, or atmospheric, pressure is applied to the passageway including surge chamber 14, as shown in FIG. 1, valve 13 will be closed and valve 15 will be opening thus dropping any loose material in chamber 14 to a discharge zone below valve 15. At the next step in the cycle when lower or vacuum, pressure is applied in the surge chamber as shown in FIG. 2, valve 13 will be opened or caused to open under the combined effect of the vacuum externally of valve 13 and the pressure of fine material pressing from the inside of valve 13. At the same time, the lips 15a, 15b of valve 15 will be tightly closed by the vacuum inside valve 15 and the higher pressure outside of it. During this condition of the valves material will drop from chamber 10 into chamber 14 without loss of vacuum from chamber 10 and its associated pneumatic system.

Obviously by choice of size of surge chamber 14 and the timing of the periods of high and low level of pressure fluid in chamber 14 many variations in loads may be accommodated.

What is claimed is:

1. Discharge valve structure for handling finely divided dry material having a reservoir chamber under vacuum and below it a surge chamber of constant volume comprising rigid walls forming an air-tight passageway having an inlet opening at its upper end for attachment to said reservoir chamber and having an outlet opening at its lower end, a first valve and a second valve each controllable by differential pressures on the upstream and downstream sides thereof, each of said valves comprising coacting lips of flexible rubberlike material extending from a sleeve with a smooth through opening, said lips being sufficiently soft and flexible to seal around any finely divided material caught between them, coacting pairs of said lips having planar terminal portions engaging to completely close said valve, said lips adapted to be closed and opened by differential pressure effective when greater externally of the valve to press said lips together in closed relationship, and effective when greater internally of the valve to part said lips, said first valve having its upstream side internally in communication with said inlet opening and having its downstream side externally exposed in said surge chamber passageway, said second valve having its upstream side internally in communication with said surge chamber passageway at said outlet opening and its downstream side externally in a discharge zone, and the sole operating means for said discharge structure consisting of conduit means connectable in one position between said surge chamber passageway and a vacuum for causing fluid pressure in said surge chamber passageway having a level less than the pressures at the inlet end of said surge chamber passageway and at said discharge zone, whereby to cause opening of said first valve and closing of said second valve, and connectable in a second position between said surge chamber passageway and a source of pressure fluid at least sufficient to close said valve lips of said first valve and to open said valve lips of said second valve, said pressure fluid then effective through said finely divided dry material to actuate said valves, the parts being so constructed and arranged that the flow of finely divided material by gravity through said valves is controlled without clogging of said valves by particles of said material and solely by change of fluid pressure in said surge chamber.

References Cited UNITED STATES PATENTS 2,723,057 11/1955 Golden 222-442 3,121,578 2/1964 Moses 222-494 X STANLEY H. TOLLBERG, Primary Examiner. 

1. DISCHARGE VALVE STRUCTURE FOR HANDLING FINELY DIVIDED DRY MATERIAL HAVING A RESERVOIR CHAMBER UNDER VACUUM AND BELOW IT A SURGE CHAMBER OF CONSTANT VOLUME COMPRISING RIGID WALLS FORMING AN AIR-TIGHT PASSAGEWAY HAVING AN INLET OPENING AT ITS UPPER END FOR ATTACHMENT TO SAID RESERVOIR CHAMBER AND HAVING AN OUTLET OPENING AT ITS LOWER END, A FIRST VALVE AND A SECOND VALVE EACH CONTROLLABLE BY DIFFERENTIAL PRESSURES ON THE UPSTREAM AND DOWNSTREAM SIDES THEREOF, EACH OF SAID VALVES COMPRISING COACTING LIPS OF FLEXIBLE RUBBERLIKE MATERIAL EXTENDING FROM A SLEEVE WITH A SMOOTH THROUGH OPENING, SAID LIPS BEING SUFFICIENTLY SOFT AND FLEXIBLE TO SEAL AROUND ANY FINELY DIVIDED MATERIAL CAUGHT BETWEEN THEM, COACTING PAIRS OF SAID LIPS HAVING PLANAR TERMINAL PORTIONS ENGAGING TO COMPLETELY CLOSE SAID VALVE, SAID LIPS ADAPTED TO BE CLOSED AND OPENED BY A DIFFERENTIAL PRESSURE EFFECTIVE WHEN GREATER EXTERNALLY OF THE VALVE TO PRESS SAID LIPS TOGETHER IN CLOSE RELATIONSHIP, AND EFFECTIVE WHEN GREATER INTERNALLY OF THE VALVE TO PART SAID LIPS, SAID FIRST VALVE HAVING ITS UPSTREAM SIDE INTERNALLY IN COMMUNICATION WITH SAID INLET OPENING AND HAVING ITS DOWNSTREAM SIDE EXTERNALLY EXPOSED IN SAID SURGE CHAMBER PASSAGEWAY, SAID SECOND VALVE HAVING ITS UPSTREAM SIDE INTERNALLY IN COMMUNICATION WITH SAID SURGE CHAMBER PASSAGEWAY AT SAID OUTLET OPENING AND ITS DOWNSTREAM SIDE EXTERNALLY IN A DISCHARGE ZONE, AND THE SOLE OPERATING MEANS FOR SAID 